Re: [Haskell-cafe] Re: Translating perl -> haskell, string "fill ins" with an error on invalid inputseems awfullycomplex. Is there a way to simplify?

Claus and Evan ++; that was very helpful. FWIW, my gut feeling is that Claus's first version was easier to understand than the revision with printf, which seems to me to involve a lot more monadic wizardry (Functor, MonadError, fmap, mapm). The first version, which just used maybe, was clear to me within seconds. But again, I learned a lot. Thanks.